Hat
Rock is a prominent landmark on the south shore of Lake
Wallula about nine miles east of the town of Umatilla, along the
Columbia River. It is this rock that Meriwether Lewis and
William Clark noted in their journals,
and that it looked much like the shape of a hat. It was
October 19, 1805 that the explorers set foot on what is now Umatilla
County, Oregon. The state acquired the land in 1951 and
created the Hat Rock State Park.

Clark may have
been the first to set foot in Umatilla County. He was
accompanied by Sacagawea, her
husband Charbonneau and two chiefs who were acting as guides for the
group: Twisted Hair and Tetoharsky.